The Affects of Reduced Oxygen and Carbon Dioxide on Plant Growth and Survival

We are researching how reduced Oxygen and Carbon Dioxide levels could affect the growth and survival of a plant.
Eli Mark, Ryan Duong
William D. Pratt School
Grade 8

Presentation

No video provided

Problem

Our Problem

We know that plants need CO₂ to preform photosynthesis, and O₂ to preform cellular respiration. But what if we were to limit the amount of O₂ and CO₂ available to a plant? This leads us to the question we are trying to answer in this project, which is:

How does reducing the amount of Carbon Dioxide and Oxygen a plant is exposed to affect its growth and survival?

Our Hypothesis

We already know plants require CO₂ and O₂ in order for them to preform processes that allow them to live, which is why we believe it is highly unlikely a plant could survive in such conditions. This can lead us to our Hypothesis, which is:

If a plant is exposed to less CO₂ and O₂, then it will likely not survive because these gases are needed for processes for the plant to survive.

Method

THIS IS NOT APPLICABLE TO OUR PROJECT.

Our project is research based, and does not require a Method as we will not be preforming any experiments. Instead, we will be collecting research and data information from scientists that have already preformed such experiments.

Research

From multiple sources and research from other scientists, If a plant lacks oxygen, we discovered that:

  • If a plant lacks oxygen, it can struggle with preforming Aerobic Respiration 
  • This causes the plant to be affected by Hypoxia which is a life threatening condition caused by lack of oxygen, and If time persists, it can turn into Anoxia
  • Because the plant lacks oxygen, it will not be able to preform the life sustaining processes in order to create ATP 
  • Because of this, the plant will eventually run out of Cellular ATP
  • The only other way a plant could create ATP is via Glycolysis
  • However, Glycolysis is not capable of sustaining the plant for a long period of time
  • This is because it uses reserve energy and only creates a small amount of ATP compared to the energy used, and only increases starvation
  • There is 1 positive when a plant lacks oxygen
  • A natural enzyme known as RuBisCo receives more carbon dioxide, decreasing photorespiration
  • However, the negatives outweigh the positives
  • If there is still a lack of oxygen after a certain period of time (depends on plant), it will die
  • Even if a plant is reintroduced into a environment with stable oxygen levels after having low oxygen amounts, it can actually damage the plant further, causing reoxygenation stress
  • This is because the metabolic system of the plant is so heavily damaged that it causes energy imbalances inside the plant
  • Some tissues (ex. Roots, Mitochondria, Phloem) that are damaged from lack of oxygen for a long period of time may not be able to fully recover, thus damaging the overall health of the plant

From multiple sources and research from other scientists, If a plant lacks Carbon Dioxide, we discovered that:

  • If a plant lacks Carbon Dioxide, the rate of photosynthesis is reduced
  • This causes the plant to create less glucose and eventually stop creating it
  • This is because a natural enzyme known as RuBisCo cannot function well without Carbon Dioxide
  • Lack of Carbon Dioxide causes the plant to rely more on Photorespiration
  • This is because normally, RuBisCo reacts with Carbon Dioxide instead of Oxygen, but since there is little Carbon Dioxide, it reacts with Oxygen more 
  • The process of photorespiration causes the plant to not only lose energy, but it also wastes carbon which is why it is often seen as a wasteful process
  • It does have 1 benefit however, as it helps detoxify the plant

Data

A table using data we found that compares the affects of low oxygen conditions to normal conditons

Proccess/Parts Plant under normal conditions Plant under low oxygen conditions The effects
Photosynthesis Functions normally and produces glucose and oxygen as normal Doesn’t directly affect photosynthesis, but affects processes are needed for photosynthesis to occur Slows glucose production, and affects ATP availablility 
Cellular Respiration Functions normally, creates a average of 36-38 ATP per glucose molecule Aerobic Respiration no longer functions, relies on Glycolysis and fermentation as ATP producer Slows ATP production, causes a energy shortage and metabolic damage, and if time persists, death
Glycolysis Acts normal, produces 2 ATP through its part in cellular respiration Becomes a major source of ATP, but is largely ineffective because of its low ATP output Only increases starvation in the plant, and is not self sustainable
Roots  Functions as normal and absorbs nutrients and water for the plant Can no longer preform aerobic respiration, and water and nutrients are absorbed slower Because the roots cannot absorb oxygen from the ground, they can no longer preform aerobic respiration and thus ATP production is slowed 

A table using data we found that compares the affects of low carbon dioxide to normal conditions

Proccess/Parts Plant under normal conditions Plant under low carbon dioxide conditions The effects
Photosynthesis Functions normally and produces glucose and oxygen as normal Causes photosynthesis to slow or halt because carbon dioxide is required for photosynthesis Glucose is produced at slower rates, and the plant grows slower or completely stops
Photorespiration Functions at a lower rate and therefore uses less energy  The rate of Photorespiration increases because RuBisCo starts to combine with oxygen instead of carbon dioxide Causes the plant to not only waste energy but also carbon, although it detoxifys the plant from harmful buildups of toxins 
Stomata Works normally, releases oxygen and absorbs carbon dioxide  Opens wider to allow for more carbon dioxide to enter the plant Since the Stomata is open wider, this causes the plant to lose more water via transpiration
Roots  Functions as normal and absorbs nutrients and water for the plant Cannot absorb as much water and nutrients because they lack energy The plant becomes affected by nutrient deficiencies because the roots arent absorbing enough

Conclusion

A Analysis of our data

After careful and precise analysis of our research and data findings, we found that if a plant lacks either oxygen or carbon dioxide, they cause similar negative effects on a plant’s growth and potential survival. Plants that are exposed to these conditions usually have lower ATP and glucose production because of the importance of these gases in self sustaining processes in a plant. Multiple processes, like photosynthesis, aerobic and cellular respiration, and the calvin cycle are all heavily, but not always directly, impacted by a lack of these gases. Each of those processes are needed for the self sustainability of a plant and when they can’t function properly, the plant cannot create enough glucose and ATP for its survival. If a plant is left in such a enviroment for a long period of time, multiple parts of a plant can be damaged, and the plant will eventually die. Even If a plant is re-exposed to a enviroment where these gases are in a ambient, natural state, it can actually damage the plant further. However, re-exposure to oxygen causes more damage compared to re-exposure to carbon dioxide. Overall, a lack of either of these gases can, and will likely cause major damage to a plant’s metabolic system and tissues, which leads us to our conclusion.

Our Conclusion

In conclusion, the survival and growth of a plant is severely hindered by a lack of these gases, which technically proves our hypothesis, in which we said a plant will likely not survive if these gases aren’t present because of their importance in processes for the self-sustainability of a plant. However, it really matters based of the scenario. If a plant is left with a lack of oxygen or carbon dioxide for a short period of time, it shouldn’t be as life threatening than if a plant is left in such a environment for a longer period of time. It also matters on the type of plant, in which C3 type plants are the vulnerable to this type of scenario. Therefore, a plant requires both these gases in ambient conditions in order for its long term growth and survival.

Citations

Citations and references list

Research and project development

Images

Acknowledgement

We would like to acknowledge:

Our CYSF Coordinators Mr. Francis Hagen and Mr. Ryan Badr for their assistance throughout the development of this project.